Software applications can edit content items such as images, video, audio, documents, and the like. Content items, such as images, can be captured using devices such as digital cameras, stored as images files, e.g., in JPG format, and transferred to storage devices. A software application can retrieve an image file stored in a storage device and display the image file on a display device of a computer system. The images can have one or more attributes, e.g., sharpness, brightness, color, and the like, and each attribute can be assigned a value. Users can edit the appearance of an image by altering the attribute values of the corresponding image using user interface controls offered by a software application.